1. Define wavelength. What unit is it measured in?  2. Define frequency. What unit is it measured in?  3. Complete the following sentences:     The higher the frequency of a wave, the greater the                 it has.     The shorter the wavelength of a wave, the greater the              it has.  4. Define a transverse wave.  5. Define a longitudinal wave.  6. Light is a transverse wave, true or false?      Sound is a longitudinal wave, true or false?  7. What type of wave is ultrasound, explain.